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SAO PAULO, Brazil | Brazil’s president says Iran’s agreement to a nuclear fuel deal he helped craft proves his nation finally has become a new global power broker.

Yet most of the credit headed Brazil’s way may well go to Luiz Inacio Lula da Silva himself. The leader, famously popular at home and abroad, is leaving office soon to a more obscure successor even as he looks for his own new challenges.

“Clearly this is a huge political home run for Lula,” said Christopher Garman, who heads Latin American research for the Eurasia Group consulting firm in Washington. “He has rounded up the end of his term in a big way: He used his personal political capital and is playing a role in the Middle East.”

Mr. Silva is a long-standing icon of Latin America’s Marxist-influenced left who enchanted investors by embracing market-friendly policies as president. With a jovial, plain-talking style forged as a labor leader, he has bonded with George W. Bush and with Venezuela’s Hugo Chavez. He has traded jokes with Barack Obama and bear hugs with Iran’s Mahmoud Ahmadinejad.

Mr. Silva portrayed the deal as a victory for his own nation and for another emerging power, Turkey, which has opposed U.S. and European efforts to impose sanctions on Iran for its nuclear-fuel enrichment. Analysts said their stand may have made it easier for Iran to accept a compromise that might have looked like a capitulation if it had been brokered by a less friendly country.

Mr. Silva has long urged a greater global role for developing nations — and a bigger place in a United Nations now dominated by a handful of countries that are permanent members of the Security Council.

“Brazil believed that it was possible to reach a deal,” Mr. Silva said last week on his weekly radio program, recorded in Tehran after the deal was signed. “I think that diplomacy came out victorious today. I think it was a result that shows we can build peace through dialogue.”

It’s not clear if the deal will satisfy the international community, though it is similar to a U.N.-drafted plan, backed by Washington and its allies, meant to deprive Iran of enough stocks of enriched uranium to produce a nuclear weapon.

The Turkish-Brazilian negotiating effort bucked the wishes of a skeptical White House. While Washington initially said the outcome could be a “positive step,” Iran then said it would keep enriching uranium on its own, something that could help it develop a nuclear weapon.

Even though the deal pushed forward by Mr. Silva may go nowhere, just getting an agreement out of Iran was an international coup for Brazil’s first working-class president, who repeatedly has argued that his country has earned the right to a permanent, prominent role in international affairs.

During the seven years of Mr. Silva’s presidency, Latin America’s largest economy has seen solid growth, its international reserves have ballooned from $38 billion to $240 billion, inflation has been tamed, and about 20 million people have been lifted from poverty.

Brazil also won the contests to host both soccer’s World Cup in 2014 and the 2016 Olympic Games in Rio de Janeiro.

But Brazil’s future influence could dim with the departure of Mr. Silva’s star power. The leading candidates to succeed him are barely known outside Brazil and don’t have his charisma. Whoever wins is likely to focus initially on domestic affairs.

Mr. Silva’s favored successor is Dilma Rousseff, his former chief of staff. A one-time revolutionary who was tortured during the nation’s 1964-1985 dictatorship, she has never run for office before.

The other main candidate, former Sao Paulo state Gov. Jose Serra, is seen as a capable but bland technocrat.

Either will have to spend months stitching together alliances among the numerous parties expected to win seats in Brazil’s Congress and will face problems ranging from divvying up revenues from new offshore oil finds to reforming Brazil’s byzantine labor and tax rules.

It could take them years to build up the international clout Mr. Silva won through frequent trips abroad, and with huge domestic popularity, now higher than 80 percent, that translated into global respect.

“Does the Iran deal mean Brazil will play a significant role after Lula? I think it remains to be seen,” Mr. Garman said.

Mr. Silva has said he won’t publicly second-guess the actions of his country’s next president but has dropped only hints of what he wants to do next.

He has brushed aside suggestions he could become secretary-general of the United Nations or president of the World Bank but has said he wants to promote Latin American integration and use Brazil’s experience in easing misery and boosting growth to foster development in Africa.

He’s not immune to controversy. Last year, the tough-talking Mr. Silva made headlines when he blamed the global financial meltdown on “white people with blue eyes” while standing next to Britain’s prime minister.

Analysts agreed the Iran deal could help catapult him into nearly any international leadership position he wants.

“Will Lula use this capital to propel himself into another position? Of course. He’ll be an ex-president in search of a role he does not want to abandon,” said Alexandre Barros, who runs the Early Warning political risk group in Brasilia.